Rock-drill.



No. 7963890. PATENTED AUG. 8, 1905. J. T. BLAGKETT.

ROCK DRILL.

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PATENTED AUG. 8

J. T. BLAGKETT.

ROCK DRILL.

APPLIOATION FILED SEPT. 15, 1904.

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N0. 796,890. PATENTED AUG. 8, 1905.

Q J. T. BLAGKETT.

ROCK DRILL.

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11 10 fi i a 4 3&4 I n Wm 1 ers UNITED STATES PIEENT OFFICE.

ROCK-DRILL.

Specification of Letters Patent.

Patented Aug. 8, 1905.

Application filed September 15, 1904. Serial No. 224,596.

To all whom it may concern.-

Be it known that I, JOHN THoMAs BLACKETT, a subject of the King of Great Britain and I reland, residing at Ivy House, Guisborough, in

the county of York, England, (whose postotfice address is Ivy House, Guisborough, in the county of York, England) have invented certain new and useful Improvementsin Rock- Drills; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertainsto make and use the same.

The object of my invention is the production of a portable power-drill suitable for drilling ironstone or the like substances.

The screw-bar which holds and drives the drill is mounted in a sleeve, in the inside of which is a key or feather, which feather fits into a groove in the screw bar. The said sleeve is driven by an air, electric, petrol, or the like motor. The feed is obtained by fixing on some portion of the motor-casing a frame carrying a threaded nut, so that when the motor is rotating the sleeve the screw-bar is advancing through the nut, giving the necessary forward motion to the drill.

An important feature of the invention consists in providing for the disengagement of the nut from the screw-bar to enable the latter to be rapidly withdrawn by hand, and for this purpose the nut is made in halves, and the halves of the nut are operatively connected to each other through links and a lever,

whereby the nut can be opened and closed, and when the nut is opened the screwbar may be rapidly withdrawn.

A further feature of the mechanism consists in constructing and arranging the parts of the feed-nut and its casing so that should the thread on either half of the feed-nut become worn the half-nut can be easily replaced by a new one without the aid of a skilled mechanic.

In the accompanying drawings, Figure 1 is a partial longitudinal section of the complete rock-drilling machine, showing the crankshaft of the motor, the driving-gear, the feednut, and the drill socket and spindle. Fig. 2 is asectional view of Fig. 1, taken on line a a looking in the direction of the arrow. Fig. 3 shows a sectional elevation of my improved feed-nut and, its casing with the parts in position to give the necessary feed to the drillspindle. Fig. 4 is a vertical section of Fig.

3, taken on the line b b and looking in the direction of the arrow; and Fig. 5 is a plan view of the feed-nut mechanism and casing with the operating-lever shown in section.

The same reference-numerals indicate like parts in the several figures of the drawings.

Referring tothe drawings, 1 is the drillspindle, and 2 the feed-nut casing.

3 4 are the halves of the split feed-nut, and 5 is their operating-lever, which lever is pivoted at 6 (at its lower end) to a block or the like '7, screwed or otherwise detachably fastened to the upper half 3 of the feed-nut. To a block 8, detachably attached to the lower half of the feed-nut, are pivoted links 9 9, which links are also pivoted to the operatinglever 5 at 10 10.

11 is a shoulder or stop on the block 7, against which the operating-lever 5 or the connecting-pivot 10, comprised in such lever, abuts when the parts are in the position shown.

18 is an extension on the feed-nut casing, which may screw or otherwise lit in the motorcasing 14.

22 22 and 23 23 are metal straps or bands across the top and bottom of the feed-nut casing, respectively, which are attached to the casing or to lugs 2 1 thereon by screws, as shown, or in any other convenient manner.

The motor driving the drill-spindle may be of any convenient, known, or suitable construction; but I prefer to employ a reversible compressed-air motor. 15 is a sleeve which is driven from or by the crank-shaft 16 of said motor through pinion 18 and gear-wheels 19, 20, and 21. Said sleeve 15 is provided on its inside with a key or feather 17, which fits in a groove or guideway, said key or feather being the means by which the rotary motion derived from the motor is transmitted to the drill-spindle or screw-bar, while at the same time permitting said spindle to move longitudinally in said sleeve in the usual way.

The working of my invention is as follows: Assuming the motor to be driving the drillspindle, so that it will screw or feed itself forward through the split feed-nut, and that it is desired to rapidly withdraw the drill from the bore-hole, the revolution of the drill-spin dle is stopped by cutting off the supply of power from the motor. It is now necessary to disengage the feed-nut'from the drill-spindle. To do this, the lever 5 is pulled over in the right-hand direction with the parts in the positions shown in Fig. 3, (left-hand direction with parts as shown in Fig. 1,) and the lower half 40f the feed-nut is thus forced away from the drill-spindle through the links 9 9, pivoted to the lever, moving over and downwardly with said lever until said half-nut t by abutting against the straps 23 23, attached to the casing 2, can move no farther. The continued movement of the lever 5 will then cause the upper half 3 of the feed-nut to be lifted clear ofv the drill-spindle, thus freeing said spindle and allowing the drill to be rapidly withdrawn by hand from the bore-hole. By operating the lever 5 in the reverse direction that is, moving it into the position shown in Fig. 1-the halves of the feed-nut will be again caused to engage the drill-spindle and allow the drill to be again fed forward when the motor is again put into operation. It is obvious that should it not be desired to withdraw the drill-spindle rapidly from the borehole by disengaging the halves of the feednut from it and withdrawing said spindle by hand the direction of revolution of the motor may be reversed, and thus the spindle will screw itself backward through the feed-nut.

When the thread of the feed-nut becomes worn, to renew the nut the drill-spindle is first withdrawn therefrom. It is then only necessary to remove the pair of straps 22 22 or 23 23, as desired, by withdrawing the screws holding such straps to the casing, when the nut can be withdrawn from the casing. The halves of the nut are then opened, and by withdrawing the screws holding blocks 7 or 8 the respective half-nuts may be detached from their operating mechanism and fresh nuts substituted. WVhen the thread on the nut becomes worn slightly and it is desired to take up such wear, the screws holding the blocks 7 and 8 to the respective halves of the nut may be loosened and strips of tin or other suitable material may be inserted between the blocks 7 and 8 and the halves of the nut, thus taking up the wear.

It is obvious that instead of employing the straps 22 22 23 23 and the lugs 24: bolts may be employed, passing through the casing at the four corners at which the straps are 10- cated in the embodiment of my invention shown in the drawings, and such bolts would perform the same functions as the straps shown in the drawings by limiting the movement of the halves of the nut and by being easily removable when it is desired to withdraw the nut from its casing.

What I claim, and desire to secure by Letters Patent, is

1. The combination, with a revoluble feedscrew, of a stationary feed-nut casing, a feednutformed in two sections which engage with the said screw and which are slidable in the said casing, an operating-lever pivoted to one nut-section, a link extending crosswise of the feed-screw and pivoted to the said lever and to the other nut-section, and a stop arranged in the path of the last-said nut-section, whereby the nut-sections are disengaged from the feed-screw one after the other.

2. The combination, with a revoluble feedscrew, of a stationary feed-nut casing, a feednut formed in two sections which engage with the said screw and which are slidable in the said casing, an operating-lever pivoted to one nut-section, links-extending crosswise of the feed-screw and pivoted to thesaid lever and to the other feed-nut section, and stops secured to the end portions of the said casing in the paths of the said nut-sections.

. In testimony whereof Iaffix my signature in presence of two witnesses.

JOHN THOMAS BLACKETT.

Witnesses:

J. GRooM, W. H. LINSON. 

